ツチ骨 （ つちこつ、英：malleus ）
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The malleus, or hammer, is a hammer-shaped small bone or ossicle of the middle ear. It connects with the incus, and is attached to the inner surface of the eardrum. The word is Latin for 'hammer' or 'mallet'. It transmits the sound vibrations from the eardrum to the incus (anvil).
【Structure】
See also: Ossicles
The malleus is a bone situated in the middle ear. It is the first of the three ossicles, and attached to the tympanic membrane. The head of the malleus is the large protruding section, which attaches to the incus. The head connects to the neck of malleus. The bone continues as the handle (or manubrium) of malleus, which connects to the tympanic membrane. Between the neck and handle of the malleus, lateral and anterior processes emerge from the bone. The bone is oriented so that the head is superior and the handle is inferior.
【Development】
Embryologically, the malleus is derived from the first pharyngeal arch along with the incus. It grows from Meckel's cartilage.
【Function】
Main article: Hearing
The malleus is one of three ossicles in the middle ear which transmit sound from the tympanic membrane (ear drum) to the inner ear. The malleus receives vibrations from the tympanic membrane and transmits this to the incus.
【 語 句 】
・ossicle：小骨 ・middle ear：中耳 ・incus：キヌタ骨 ・eardrum：鼓膜 ・tympanic membrane：鼓膜 ・neck of malleus：ツチ骨頸 ・handle：ツチ骨柄 ・embryologically：発生学的に ・be derivede from～：～に由来する ・pharyngeal arch：
鰓弓 ・Meckel's cartilage：メッケル軟骨
